Sulfonamidobenzimidazoles



Patented Nov. 5, 1946 SULFONAMIDGBENZEMIDAZOLES Charles F. H. Allen, Rochester, N. Y., and Alan Bell, Oak Ridge, Tenn, assignors to Eastman Kodak Company, Rochester, N. Y, a corporation of New .llersey No Drawing. Application April 20, 1944, Serial No. 531,981

3 Claims.

together with methods of preparation of these compounds and their intermediates.

Example 1.-Preparation of intermediate compound, 3,4-diaminobenzenesulfonamide,

A mixture of parts of 3-nitro-4-aminobenzenesulfonamide, parts of alcohol, 15 parts of sodium hydrosulfite, and parts of water was heated on the steam bath for 2 hours, and evaporated to dryness. The residue was extracted with hot alcohol, filtered, and the product from the extract finally crystallized from water. The yield was 2 parts, M. P. 174-175 C. (Analysis: Calcd. for CsHeOzNsS: N, 22.46. Found: N, 22.59.) 3,4- diaminobenzenesulfonamide can also he obtained in a yield of by reducing an alcoholic solution of the nitro compound by hydrogen in the presence of Raney nickel.

Example 2.--5-sulfonamido-benzimidazole or 5-sulfamyl-benzimidazole,

A mixture of 1 part of 3,4-diaminobenzenesulfonamide, 1 part of sodium acetate, 7 parts of acetic acid, and 3 parts of water was refluxed for 3 hours, and then heated in an open vessel on the steam bath; this resulted in the formation of a paste. The paste was dissolved in water, decolorized and filtered, and the filtrate concentrated and allowed to cool. The yield was 0.5 part. This crude compound wa recrystallized from 95% alcohol. The purified product melts at 221 C. (Analysis: Calcd. for C'sH902N3S! N, 19.90. Found: N, 19.54.)

Example 4.Preparation of intermediate compound, N -(2'- hydroxyphenyl) B-nitrosulfanilamide,

I coma-Q A mixture of 17 parts of 3-nitro-4-aminoloen- -zene sulfonyl chloride, 7.8 parts of o-amino- N Omrso v \C SH A solution of 8.6 parts of N -(2'hydroxyphenyl)-3-nitrosulfanilamide in 25 parts of alcohol was reduced in the presence of a Raney nickel catalyst at 40 lbs. hydrogen pressure at C. The solution of the resulting diamine was cooled, filtered, and, after the addition of 5 parts of carbon disulfide and enough 40% sodium hydroxide solution to make alkaline, was heated over night on the steam bath. The solution was then concentrated to a small volume, diluted with Water and acidified with hydrochloric acid. The precipitate was filtered, washed and dissolved in warm sodium carbonate solution. After treatment with decolorizing carbon and acidifying, the

product was filtered, washed and dried. The yield was 4.8 parts, M. P. 265 C., with decomposition. (Analysis: Calcd. for C13H110N3S22 N,

13.08. Found: N, 12.82.)

Example 6.--Preparation of intermediate compound, N -(4' acetaminophenyl)-3-nitrosulfanilamide,

SOaNHONHCO H3 CHaCONH-O-NHSOz-[I \C N/ 3 An alcoholic solution of 12 parts of N -4'-acetaminophenyl)-3-nitrosu1fanilamide was reduced with hydrogen at 90 C. and 40 lbs. pressure in the presence of a Raney nickel catalyst. To the resulting solution of diamine, parts of carbon disulfide was added, and sufiicient 40% sodium hydroxide to make alkaline. After heating for 12 hours on the steam bath, the solution was evaporated to dryness, and the residue was dissolved in warm, dilute sodium hydroxide and treated with decolorizing carbon. Upon acidification with acetic acid, 8.5 parts of 2-mercapto-5-sul- 4- anilido) '-benzimidazole or 4'-amino -5-phenylsulfamyl-2-mercapto-benzimidazole N NHz-ONHSOv-U C SH A mixture of 12 parts of 2-mercapto-5-sulfon- (4'-acetaminoani1ido)-benzimidazo1e, 24 parts of concentrated hydrochloric acid and 100 parts of alcohol was heated on the steam bath for 2 hours; a clear solution resulted. It was diluted with water and made just basic (Congo red no longer changed color). The product (12 parts) was filtered, Washed and dried, M. P. 240-242 C. with decomposition. (Analysis: Calcd. for

(3149. 21; H, 3.48. Found: C, 48.84; H, 3.61.)

While we have given certain illustrative examples, it will be understood that other substituents than those shown may be present on the nitrogen of the sulfonamido (sulfamyl) group, and/or on the carbon in the 2-position of the heterocyclic ring.

What we claim as our invention and desire to be secured by Letters Patent of the United States l. 2-mercapto S-sulfon-(2'-hydroxyanilido)- benzimidazole.

2. 2-mercapto 5 benzimidazole.

3. A compound having the structural formula:

in which R is a member selected from the class consisting of H, hydrocarbon, nd substituted hydrocarbon groups, the substituent in the hydrosulfon- (4'-aminoani1ido) carbon group being selected from the class conion-(4' acetaminoanilido) -benzimidazole was sisting of hydroxyl, ta a amino p formed.

Example 8.2-mercapto-5-sulfon-(4'--amino- CHARLES. F. H. ALLEN. ALAN BELL. 

